Merge pull request #3 from UbiqueInnovation/bugfix/zxing-parallel-dec…

…oding

Read-Only ByteBuffer & Error Codes

example/src/main/java/ch/ubique/qrscanner/example/ComposeActivity.kt

@@ -5,7 +5,13 @@ import android.os.Bundle
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.wrapContentWidth
 import androidx.compose.material.Button
 import androidx.compose.material.Slider
 import androidx.compose.material.Text
@@ -16,6 +22,7 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
 import ch.ubique.qrscanner.compose.QrScanner
 import ch.ubique.qrscanner.example.databinding.ActivityComposeBinding
+import ch.ubique.qrscanner.mlkit.decoder.MLKitImageDecoder
 import ch.ubique.qrscanner.scanner.QrScannerCallback
 import ch.ubique.qrscanner.state.DecodingState
 import ch.ubique.qrscanner.zxing.decoder.GlobalHistogramImageDecoder
@@ -44,7 +51,7 @@ class ComposeActivity : AppCompatActivity() {
 		binding.composeView.setContent {
 			Box(Modifier.fillMaxSize()) {
 				QrScanner(
-					imageDecoders = listOf(GlobalHistogramImageDecoder(), HybridImageDecoder()),
+					imageDecoders = listOf(MLKitImageDecoder(), GlobalHistogramImageDecoder(), HybridImageDecoder()),
 					scannerCallback = scannerCallback,
 					modifier = Modifier.fillMaxSize(),
 					isFlashEnabled = isFlashEnabled.collectAsState(),

qrscanner-core/src/main/java/ch/ubique/qrscanner/scanner/ErrorCodes.kt

@@ -1,5 +1,13 @@
 package ch.ubique.qrscanner.scanner
 
 object ErrorCodes {
+	/**
+	 * Happens when the image proxy input has the wrong format (YUV format is expected)
+	 */
 	const val INPUT_WRONG_FORMAT = 1
+
+	/**
+	 * The image decoder failed to read the image proxy input
+	 */
+	const val INPUT_READ_FAILED = 2
 }

qrscanner-zxing/src/main/java/ch/ubique/qrscanner/zxing/decoder/ZXingImageDecoder.kt

@@ -6,7 +6,17 @@ import androidx.camera.core.ImageProxy
 import ch.ubique.qrscanner.scanner.ErrorCodes
 import ch.ubique.qrscanner.scanner.ImageDecoder
 import ch.ubique.qrscanner.state.DecodingState
-import com.google.zxing.*
+import com.google.zxing.BarcodeFormat
+import com.google.zxing.Binarizer
+import com.google.zxing.BinaryBitmap
+import com.google.zxing.ChecksumException
+import com.google.zxing.DecodeHintType
+import com.google.zxing.FormatException
+import com.google.zxing.LuminanceSource
+import com.google.zxing.MultiFormatReader
+import com.google.zxing.NotFoundException
+import com.google.zxing.PlanarYUVLuminanceSource
+import com.google.zxing.RGBLuminanceSource
 import com.google.zxing.common.GlobalHistogramBinarizer
 import com.google.zxing.common.HybridBinarizer
 import kotlinx.coroutines.Dispatchers
@@ -31,18 +41,22 @@ abstract class ZXingImageDecoder(
 
 	override suspend fun decodeFrame(image: ImageProxy): DecodingState = withContext(Dispatchers.IO) {
 		if (image.format in yuvFormats && image.planes.size == 3) {
-			val buffer = image.planes[0].buffer
-			val data = buffer.toByteArray()
-			val source = PlanarYUVLuminanceSource(
-				data,
-				image.planes[0].rowStride,
-				image.height,
-				0,
-				0,
-				image.width,
-				image.height,
-				false
-			)
+			val source = try {
+				val buffer = image.planes[0].buffer.asReadOnlyBuffer()
+				val data = buffer.toByteArray()
+				PlanarYUVLuminanceSource(
+					data,
+					image.planes[0].rowStride,
+					image.height,
+					0,
+					0,
+					image.width,
+					image.height,
+					false
+				)
+			} catch (e: Exception) {
+				return@withContext DecodingState.Error(ErrorCodes.INPUT_READ_FAILED)
+			}
 
 			return@withContext decodeLuminanceSource(source)
 		} else {